This invention relates to real-time imaging of infrared signals utilizing semiconductor materials.
The detection of radiation limited to infrared wavelengths in a region of interest, such as 3 to 5.mu.m emitted from relatively hot bodies and 8.mu.m to 12.mu.m emitted from bodies at ambient temperatures, by use of a narrow band gap semiconductor, is generally well known. Visible imaging of signals associated with such detected infrared radiation, however, has heretofore involved a considerable amount of electronic processing.
The conversion of infrared radiation into visible imaging light is disclosed, for example, in U.S. Pat. No. 4,914,296 to Reinhold et al. U.S. Pat. No. 4,157,926 to Schoolar relates, on the other hand, to the use of thin film semiconductor crystalline material for detection of infrared radiation. The design and selection of semiconductor materials for detection of radiation at infrared wavelengths is disclosed, by way of example, in U.S. Pat. Nos. 4,195,226, 4,691,107 and 4,885,620 to Robbins et al., Elliot et al., and Kemmer et al.
Methods and apparatus are also generally known in the art for the synthesis of semiconductors with desired characteristics. Such prior art apparatus include molecular beam epitaxy and vapor phase epitaxy devices enabling the growth of high quality semiconductor films and tandem positive ion accelerators by means of which the semiconductor film may be implanted with ions to obtain the desired electronic properties relating, for example, to electron mobility, carrier lifetime and band-gap gradient.
It is therefore an important object of the present invention to provide for more direct, portable and less costly real-time imaging of detected infrared radiation signals by upconversion to visible radiation involving spectral shift in wavelength of visible radiation.